A hard coating film has been used for protecting the surface of various image displays including a liquid crystal display device (LCD), an electroluminescence (EL) display device, a plasma display (PD), a field emission display (FED) and the like.
Recently, a flexible display which can maintain display performance even when it is bent like a paper by using a flexible material such as plastic, instead of a conventional glass substrate having no flexibility, gains attention as a next generation display device. In this regard, there is a need for a hard coating film which not only has high hardness and good impact resistance but also has proper flexibility, without curling at the film edges during its production or use.
Korean Patent Application Publication No. 2014-0027023 discloses a hard coating film which comprises a supporting substrate; a first hard coating layer formed on one surface of the substrate and comprising a first photocurable cross-linked copolymer; and a second hard coating layer formed on the other surface of the substrate and comprising a second photocurable cross-linked copolymer and inorganic particles distributed in the second photocurable cross-linked copolymer, and the hard coating film exhibits high hardness, impact resistance, scratch resistance, and high transparency.
However, the hard coating film having excellent impact resistance and curling properties without including a supporting substrate has not yet been developed.